Soul Swap is a warlock ability learned at level 79 for those with the Affliction specialization. It removes the shadow DoTs from the warlock's target. For a brief period of time the warlock can then transfer the DoTs over to another target and deal more instant damage.

Patch 5.4.0 (10-Sep-2013) Soul Swap no longer does any damage, and now copies damage-over-time effects instead of just moving them without needing a glyph. Copied effects now once again preserve their power and duration. Duration has been reduced to 3 seconds (down from 20 seconds).

Patch 4.0.6 (8-Feb-2011): Soul Swap can no longer be dispelled (the aura given to the warlock between swapping).